Method of preparing a magnetizable body to receive and reproduce wave frequencies



Oct. 20, 1931. R, B T, K|| |AN| 1,828,190

METHOD 0F PREPARING A MAGNETIZABLE BODY TO RECEIVE AND REPRODUGE WAVEFREQUENCIES Filed June 18, 1950 ATTORNEY Patented Oct. 20, 1931 UNITEDSTATES PATENT OFFICE RICHARD' B. T. KILIANI, 0F DETROIT, MICHIGAN,ASSIGNOR OF ONE-FOURTH TO ARTHUR GARDNER, OF DETROIT, MICHIGAN METHOD OFPREPARING A MAGNETIZABLE BODY T RECEIVE A N D REPRODUCE I FBEQUEN'CIESApplication led June 18,

My invention relates to a new and improved method of preparing amagnetizable b ody to receive and reproduce wave frequencies.

I am, of course, aware that magnctizable 'Ig bodies have heretofore beenprepared f or the purpose above stated, but, prior to my 1nvention, muchtrouble has been experlenced 1n the use of said prepared bodies, inrecelvlng, retaining and reproducinr the Wave frequen- A cies, duc tothe metho s followed 1n the preparation of such bodies.

A method for electro-magnetically recording telephone or telegraphsignals was .1nvented by Vlademar Poulsen in 1898, but with 16" themethod described and used by him, and

as improved upon from time to time by himself and others, it isimpossible to satlsfac- A torily record and reproduce speech or musicwhich will compare in quality with even the 20 poorest type of modernphonograph. He, and

others following him, described methods for erasing suchelectro-magnetic records and for preparing the magnetizable body onwhlch the record was made, for a subsequent record.

All these methods provided for moving the lnagnetizable body ast amagnet, so that 'the magnetic conditlon of the bod was brought to somesingle predetermme level.

It is a simple matter to erase a prevlous record, since merely passing ama et of whatever kind over the ma etizab e body will achieve thisobject, but t e magnetizable body is then not in a suitable magneticcondition to receive and hold a subsequent record such as is desired.

My invention contemplates a new method for erasing a previous record andfor preparing the lnagnctizable body for a subsequent record, whichbrings the body into a more suitable magnetic condition for taking andretaining a record than was achieved by the use of the prior artmethods.

Under my invention, a record on a magnetizable body may be erased ashereinafter described, the magnetizable body being thus brought into asuitable magnetic condition for a subsequent record to be made. The samemethod ma be used for preparing a magnetizable bo y on which no record.as been previously made, since this preparation WAVE 1980. Serial No.462,069.

for the following record, the body is causedv to move past a particularsystem of magneti, with the result that its magnetic condition is suchas will permit its taking and holding a record which is a true andcorrect copy of the original Waves which it is desired to record andreproduce..

A record made on and reproduced from a magnetizable body prepared bythev method aining a satisfactoryy disclosed in the present invention isin such y a condition that it may be reproduced an innumerable number oftimes and is permanently retained on the magnetizable body. Thispermanent retention of a recor-d on a body so prepared is' proven by thefact that I have conducted experiments in which I have reproducedrecords made on a body prepared in accordance with my invention, a greatnumber of times, with the ideal of simulating the effect of severalyears use. `Other methods of preparing the magnetizable body, describedand known up to this time, do not permit attaining this perfection in arecord.

The particular system of magnets above mentioned is so arranged that twoor more magnetic poles of opposite polarity act upon the magnetizablebody, so that it is lirstsubjected to the action of one pole, beingmagnetized with a certain polarity of a desired flux density, andimmediately thereafter is subjected to the action of a second pole whichmagnetizes it with the opposite polarity of a different flux density,and so on, each succeeding pole beiner of opposite polarity to the oneimmediatey preceding it, and magnetizing the wire with a different fluxdensity from that of the magnetic pole preceding it.

Any suitable means may be employed to obtain the desired effect ofopposite polarity and flux density which magnetizes the magnetizablebody in a different manner from i that of the ma etic poles immediatelypreceding and fo owing any particular pole. Among these may be mentionedpermanent Amagnets of e ual strength, but the surfaces ofelectro-magnets, the effect of ma etization of the magnetizable bodywith di erent flux densities for the' various poles which act u n it,may be obtained b using cores of di erent materials, cores o unequalcross-section, effective surfaces of unequal area, windings of the sameor a different number ofturns, energizing current of the same or ofdierent values, etc., or an combination of these or other variables wich will give the desired effect of magnetization of a certain polarityof a desired flux density, followed by magnetization of the oppositepolarity of a different flux density.

, In the accompanying drawin s:

Figs. 1 to 9 inclusive are ia'graiiimati'c views illustrating variousforms of magnetizing apparatus that rmay be employed in the practice ofmy invention; and

Fig. 10 a diagrammatic view of a form'of means for assin themagnetizable body intoclose re ations ip with the magnetizing ap aratus.

eferring to the drawings, 4 designates a magnetizable body or wire thatis to be prepared; and in the forms of Figs. 1, 2 and 3, 5 and 6designate permanent magnets of opposite polarity. Fig. 1 shows themagnets of equal ma etic flux densit and havin effective sur aces, asindicate by a and of unequal area.

Fig. 2 shows the magnets with equal effective surfaces a and c, themagnet 6 having a .windin d and a battery e to change its flux density,while Fig. 3 shows the magnets with unequal effective faces or surfaces,and having the winding and battery associated therewith for the samepurpose as the form of Fig. 2.

In Figs. 4 to 9 inclusive,I have illustrated various ways of utilizingelectro-magnets in the practice of my invention. For example, Fig. 4shows a pair of electro-magnets 7 and 8, the windings of which are of anequal number of magnetic turns, said windings being in the samedirection and in series with a batteryy 9, whereby the effect ofopposite polarity is attained with constant flux densities; and in Fig.5, the windings of said magnets 7 and 8 are each connected in serieswith a battery 10 and 11, respectively, the directions of current flowbeing opposite to produce opposite polarity.

Y Fig. 6 illustrates a similar form to that of Fig. 5, the' core of theelectro-magnet 7a, however, being of lesser cross section than the coreof electro-magnet 8, thereby providing unequal flux densities, as wellas opposite Y polarit Fig. is similar to the arrangement of Fig.

5, with the exception that the electro-magnet 8a has a smaller effectivearea m than that of the .magnet 7, so as to produce unequal flux at theregion traversed by the magnetizable body 4.

In Fig. 8, the electro-magnet 8b is provided with a greater number ofmagnetic turns for the purpose of inducing a greater flux densitytherein than the liux density of the magnet 7 and, similarly, in Fig. 9,unequal lux densities are produced by means of unequal energizingcurrents generated by the batteries 10 and 12.

Thus, it is seen that various combinations of magnets andelectro-magnets may be provided for the pur ose of obtaining oppositepolarit and ual) or unequal flux densities.

In ig. 10, and B designate two reels, from one of which, for example B,the Wire is unwound, and on the other of which (A) the wire is wound. Ais driven by suitable means (a belt drive is shown) by a motor M, whichis rovided with suitable means such as a clutc etc., to drive A or B, asdesired. 1n the exam le shown, A is pulling on the Wire, with t e resultthat it is drawn (past the magnets, generally represented at in thedirection from B to A. Reel B is not connected to the motor M in thiscase, but is retarded by a brake, not shown, to maintain a suitabletension on the wire.

In practicing my invention, the magnetizable body or wire 4 istranslated in closed proximity to any. .of the magnetic systems )ustdescribed, the effect of which is to induce a magnetism in the said bodyor wire, whereby the same is conditioned to receive and retain a recordthereon, and consisting of a series of magnetic impulses produced bysound or light waves of any range of frequencies by means of theapparatus -and method shown and described in my companion application,Serial No. 462,068.

As stated, it has been found that a magnetizable body, prepared in themanner herein set forth, will receive a magnetic record more readilythan any body prepared heretofore, or than an unprepared orde-ma-gnetized body. Also, the record received thereby will be retainedwithout becoming distorted or destroyed even when brought into contactwith itself or other record-bearing wires, as for example, upon a reel.l

I claim:

1. The method of preparin a magnetizable body to receive a record o anyrange of wave frequencies which consists in subjecting the body to theaction of three or more magnetic poles of different magnetic effect.

2. The method of preparing a magnetizable body to receive a record ofany range of Wave frequencies, which consists in subjecting the body tothe action ofA three or more magnetic poles of different olarity.

3. The method of preparing` a magnetizable body to receive a record ofany range of Wave frequencies, which consists in subjecting the body tothe action of a. plurality of magnetic oles of opposite polarity and ofdifferent ux density 4. The method of preparin a magnetizable body toreceive a record o any range of Wave frequencies, which consists insubjecting the body to the action of a magnetic pole to impart to thebody a magnetism in one direction and then subjecting the body to amagnetic pole of different polarity than the first to impart a magnetismto the body of different value and in the opposite direction.

5. The method of preparing a magnetizable body to receive a record ofany range of Wave frequencies, which consists 1n subjecting the body tothe action of a, plurality of magnetic polesof different linx density atthe place of magnetization of the body.'

Y 6. The method of preparing a magnetizable body to receive a record ofany range of wave frequencies which consists in subjecting the body, inmotion, to the action of a plurality of magnetic poles of different fluxdensity.

In testimon whereof I aix m signature.

R CHARD B. T. LIANI.

